This week, seven semiconductor stocks are improving their overall ratings on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

This week, FSI International (FSII) is showing good progress as the company’s rating jumps from a B (“buy”) last week to an A (“strong buy”). FSI International is a supplier of processing equipment used at key production steps to manufacture microelectronics, including semiconductor devices and thin film heads. In Portfolio Grader’s specific subcategories of Earnings Growth, Earnings Momentum and Sales Growth, FSII also gets A’s. For more information, get Portfolio Grader’s complete analysis of FSII stock.

This week, Yingli Green Energy Holding Co. Ltd. Sponsored ADR (YGE) is showing significant improvement as the company’s rating hops from a C (“hold”) to a B (“buy”). Yingli Green Energy designs, manufactures and sells photovoltaic modules, and designs, assembles, sells and installs photovoltaic systems. For more information, get Portfolio Grader’s complete analysis of YGE stock.

Ambarella, Inc. (AMBA) gets a higher grade this week, advancing from a B last week to an A. Ambarella develops semiconductor processing solutions for video that enable high-definition (HD) video capture, sharing, and display. For more information, get Portfolio Grader’s complete analysis of AMBA stock.

Xilinx, Inc. (XLNX) shows solid improvement this week. The company’s rating rises from a C to a B. Xilinx designs, develops and markets programmable platforms and predefined system functions delivered as intellectual property cores. For more information, get Portfolio Grader’s complete analysis of XLNX stock.

This is a strong week for Nova Measuring Instruments Ltd (NVMI). The company’s rating climbs to B from the previous week’s C. Nova Measuring Instruments develops, produces, and markets monitoring and measurement systems for the semiconductor manufacturing industry. For more information, get Portfolio Grader’s complete analysis of NVMI stock.

First Solar, Inc. (FSLR) improves from a C to a B rating this week. First Solar designs and manufactures solar modules. For more information, get Portfolio Grader’s complete analysis of FSLR stock.

Himax Technologies, Inc. Sponsored ADR (HIMX) is seeing ratings go up from a B last week to an A this week. Himax Technologies designs and manufactures integrated circuits. For more information, get Portfolio Grader’s complete analysis of HIMX stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.